The German two-time grand slam champion, currently ranked 22nd in the world after a disappointing 2017 campaign, registered her ninth win in as many matches this year with another clinical performance against the local favourite.
It was the first individual final since Monterrey in April last year for the 29-year-old left-hander, who won the Australian and U.S. Open titles in 2016.
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"Thanks to my team for believing in me and supporting me, we had an excellent week. I am really looking forward to the rest of the year," Kerber said in a court-side interview after claiming a first title since her U.S. Open triumph.
"I am playing amazing tennis again and I am just feeling great."
After some tight early service games, Barty double-faulted to hand Kerber the first break and a 3-2 lead, and the German served out the opening set with little trouble.
The second set witnessed an early exchange of breaks before Kerber broke the Australian to love to move 4-3 ahead and picked up her 11th career title when Barty found the net after yet another powerful Kerber forehand.
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